May 11

Forging Connections and Web Sketchpad

I attended (5/11/2020) a 2 hour webinar that was very good.

It was very good. They have good goals and good guiding principles. is the main website.

Workshop agenda and links are here:

For Web Sketchpad (this is a free, web, version of Geometer’s Sketchpad, see the graphic for a good place to start.









If you append the ‘queries’ in the graphic you can get more information.

My Notes:

Webinar Forging Connections (39 here)

NSF grant

Running the webinar: Karen Hollebrands – NC state Math educator

Lead with geometry!!

There are goals and guiding principles.

5 units – intended for HS students.  There are also areas for T-Ed studs, T-ed T’s.


Karen Hollebrands, Allison McCulloch; Kristen Fye, Daniel Scher (web sketchpad developer), Scott Steketee

Identify functions activity

Points are Paired. 1 moves (independent) 1 doesn’t (dependent)

Web sketchpad

  • Came from Geometer’s sketchpad
  • Web based
  • Free for education use. Can’t make money using it.
  • Tools can be given or taken away
  • Introductory Videos
  • Tool Library
  • WebSketch Viewer
  • NOTE: there is more than 1 compass. And one is a collapsing (Euclidean!) compass
  • Web sketchpad has an interesting way

Jul 11

Minimizing Polyhedra

article on minimizing polyhedra

Jun 07


KaleidoTile is a colorful program for investigating Tilings, Symmetry, and Polyhedra.  I remember seeing it many years ago. I’m glad to see that Jeff Weeks is continuing to update it.  FREE download.

Oct 30

Ball of Whacks

Update: I turned this into a full page:  Top 8 Interesting Things to Know about the Rhombic Triacontahedron

Ball of Whacks is a geometry toy. (Available online and in toy stores that sell cool stuff.)whacks

It is a rhombic triacontahedron.  Each of the 30 rhombic faces are golden, in that the ratio of the diagonals is the Golden Ratio.

Good stuff at

It is the dual of the Icosidodecahedron (which is Archimedean), which is the Hoberman Sphere.

I have a light in my office (which was a gift from my kids) which is the rhombic triacontahedron.


Oct 25

Prince Rupert’s cube

Cut a hole in one cube so that a cube of the same size (actually one slightly bigger!) can pas through. 

Jun 20

Article: 5 Reasons Why Origami Improves Students’ Skills

5 Reasons Why Origami Improves Students’ Skills

Jun 08

I’ll be doing a Beauty of Three Dimensional Polyhedra Workshop

Beauty of Three Dimensional Polyhedra Workshop (in Celebration of the MAA’s Centennial)

MathFest at Washington, DC. Friday, August 7, 2015, 1:00-2:20 p.m., Maryland C

Description: I have long been fascinated by the Platonic and Archimedean solids and their mathematical beauty. In this workshop I will demonstrate, and we will work with, a variety of materials I’ve come across over the years for building polyhedra. For example, we’ll build with coffee stirrers (really cheap, less than 10 cents for the icosahedron), origami (about  25 cents for the Buckyball), and retail manipulatives (a few dollars for the truncated tetrahedron). We will also look at some online tools for exploring (and enjoying) the Platonic and Archimedean solids and their mathematical relationships and properties. These dynamic tools are useful is seeing how, for example, the snub icosidodecahedron is formed.  (Attendees are encouraged to bring a laptop or device to the workshop.) Included will be how the icosahedron
(this is the MAA!) can be built using three golden rectangles.

Organizer: James R. Olsen, Western Illinois University

MathFest info / Workshop info